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eggrobin/orbital elements.md Secret

Last active Nov 10, 2019
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pozine and orbital elements

Hello Eggrobin,

I am currently looking to provide realistic orbital elements for my mod. I went to the link you put in RSS Config and didn't manage to get any useful information. :/ All I get is some gibberish with many numbers and variables. Is there something i'm missing?

well, the gibberish with numbers and variables is the orbital elements :P

On http://ssd.jpl.nasa.gov/horizons.cgi, set #####Ephemeris type Orbital Elements, #####Time span start time to JD2433282.4235, stop time to JD2433282.9235, step size to 1 day, #####Table settings units to km & km/s, reference plane Earth Mean Equator and Equinox of Reference Epoch, reference system FK4/B1950.0, choose your target body and center, the page will look like

Current Settings

Ephemeris Type [change] : ELEMENTS
Target Body [change] : Mars [499]
Center [change] : Sun (body center) [500@10]
Time Span [change] : Start=JD2433282.4235, Stop=JD2433282.9235, Step=1 d
Table Settings [change] : output units=KM-S; reference plane=FRAME; reference system=B1950
Display/Output [change] : default (formatted HTML)

press Generate Ephemeris, in the Results section,

 EC= 9.326110278323546E-02 QR= 2.066908595644147E+08 IN= 2.469272426910055E+01
 OM= 3.351911063089118E+00 W = 3.321022655295415E+02 Tp=  2432959.159450385720
 N = 6.064848856918036E-06 MA= 1.693913127942378E+02 TA= 1.711555455296511E+02
 A = 2.279496999619763E+08 AD= 2.492085403595378E+08 PR= 5.935844544408656E+07

helpfully, you also get

Symbol meaning  

    JDCT     Epoch Julian Date, Coordinate Time
      EC     Eccentricity, e                                                   
      QR     Periapsis distance, q (km)                                        
      IN     Inclination w.r.t xy-plane, i (degrees)                           
      OM     Longitude of Ascending Node, OMEGA, (degrees)                     
      W      Argument of Perifocus, w (degrees)                                
      Tp     Time of periapsis (Julian day number)                             
      N      Mean motion, n (degrees/sec)                                      
      MA     Mean anomaly, M (degrees)                                         
      TA     True anomaly, nu (degrees)                                        
      A      Semi-major axis, a (km)                                           
      AD     Apoapsis distance (km)                                            
      PR     Sidereal orbit period (sec)                

so we use A, EC, IN, MA, OM, W.

BE CAREFUL, RSS/Kopernicus wants distances in metres, so you need to convert.

For further questions, come to the #RO IRC channel on espernet, https://webchat.esper.net/?channels=RO and ask me (or NathanKell if I'm asleep).

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